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Comment by simfree | Hacker News Reader

OP should have gone by percentage of battery left, and just left the car plugged in.

Not plugging in when arriving and letting the battery freeze (cold soak) overnight, unplugging after 30 minutes of 1.5kW level 1 charging and basing his entire decisions on what the car's guess-o-meter says for remaining milage is pretty crazy IMO.

Seems like OP chose to do the worst thing possible at each juncture to ensure a bad charging experience.

It is normal for cars to use 2 or 3 kilowatts (an hour or two of charging) heating the battery up to temperature in freezing conditions, but once the pack is up to temperature it charges close to normal speed.

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> and basing his entire decisions on what the car's guess-o-meter says for remaining milage is pretty crazy IMO.

What are you supposed to base it on? Does your EV come with a working crrystal ball? Should I read the car's horoscope?

I mean, really, I've read stupid statements, but blaming the user for trusting the displayed battery capacity on a device really takes the cake.

The guess-o-meter doesn't reflect the actual state of the battery, but rather what it has seen in the recent past, hence OP should toggle to battery percentage and trust that instead of a known inaccurate estimator.

If the "guess-o-meter" is so bad that it leads reasonable people to wildly wrong conclusions, I'm hesitant to blame that on the user.

If all the factors you described are understood by humans, why aren't they factored into the display algorithm? If the car is going to drain battery for an hour getting warm before it can start to charge, then say that on the display.

The car can't predict the severity of weather, whether or not your going to preheat the car or your driving style.

All of these factors combine to make the range estimator a guesstimate on both gas and electric cars.

But it could make a better guess than it does, or even leave the numerical guess untouched but give the driver other useful information. Specifically, the information you gave in your first comment.

Teslas have great big dashboard screens. There was no need to leave OP thinking that the car was unchargable unless it was brought into a warm place.

It's hardly crazy to expect that the car should display an accurate range estimate based on the current temperature.

Gas car range predictions are also regularly nonsensical. I thought this was well understood.

People have extremely high expectations of range estimates. These displays are known as Guess-O-Meters for good reason, they only account for past weather, driving conditions and style.

Perhaps that used to be a problem. The range estimates for gasoline cars that I've owned and rented in the past few years have been accurate to within a few percent, even in cold weather.

I expect that’s true over a full tank of gas but not when e.g. only 20 miles are left.

On my car (2013 mini) the range prediction is actually a more accurate indicator of how much fuel is in the tank than the (separate) fuel tank meter. Not sure why, you’d think they’d use the same input data for both, but it’s true.

By giving you a less precise fuel tank indicator (eg: 8 segment fuel display) versus xxx Miles of Range, your cajoled into trusting the estimator, and the range being so high on gas cars usually allows the estimator to end up closer to accurate thanks to bad and good economy driving and conditions averaging out.

I am all for EV, but if besides needing to take care that I plug my phone and my watch every night I must also not forget to plug in the car and if I forget, I must apologize at work for not coming in, or my kids cannot go to school... just because it easily can get to -15°C here... then it feels like a technology issue and not like me doing the worse thing possible...

If you plug in every night and miss a night you can almost certainly make it to work the next day, unless your a supercommuter with an older EV that had a small 24kWh pack.

But that's a thing you learn. Just like you learn to check your oil level before starting in a conventional vehicle. Everything has its own set of things you have to know

> Just like you learn to check your oil level before starting in a conventional vehicle.

Yeah, I (and everyone else) totally do that…

Not even once.

I’d estimate I have driven cars 10,000 times and I have never done that. Just take it to a mechanic every 5k miles. And nothing that touches the oil has ever gone wrong.

Regular EV user here - plugging it in is something you do every time you park, the way you lock your doors. It takes five seconds. Press the «open charge port» button on the charging cable and stick it in the charging socket. Done.

I’m cracking up that you’re making this sound so simple and matter of fact, but reading this description of how one is “supposed” to charge their EV makes me realize i’m many years from wanting one.

Honestly, it’s kind of a joke how badly people want to defend the tech despite its current shortcomings.

Yes, plugs are very confusing. They'll offer a course in college for the younger generations.

I think the GP was saying “it doesn’t have shortcomings”, not trying to defend any that actually exist.

Not sure why "supposed" is in quotes here. You're "supposed" to fill your car with gas by waiting til you come across a gas station, driving in, parking at a pump, getting out, pressing the button to open the gas tank, plugging in the hose, pumping gas for as long as it takes to fill the tank to the desired level, paying, and so on.

Compared to plugging in an EV at night and forgetting about it and this being sufficient for 99 percent of my driving needs, getting gas sounds like it has vastly more shortcomings and that's before you look at any of the other crappy things about it.

On the flip side my GF loves it.

When she got home late the last thing she wanted to do was to spend an extra 10-15 minutes or so filling up. Which frequently led to a panic the following day when she'd forgotten. She even ran out of gas a couple of times when she was really stressed the following day.

She much prefers the EV since it's always full. When she gets home it takes literally less than 10 seconds to plug it in. Next day it takes literally less than 10 seconds to unplug, and she never has to think about filling up for the rest of the day.

You gotta plug it in to charge, man. I don't know what you want. Just leave it plugged in whenever you can and that's it.

Filling gas and changing oil is also pretty inconvenient, it’s just habit that makes you discount it. A good EV is more convenient for everyday use. Cheaper too.

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